The major objectives of the grant proposal involves the study of plasma membrane receptors for prolactin and growth hormone, with particular emphasis on prolactin. In order to understand the interaction of prolactin and growth hormone with their receptors, studies on the further purification, and characterization of both prolactin and growth hormone receptors will be undertaken. A second major objective is the study of non-primate placental lactogens in the rat, sheep, goat and cow. Purification and characterization studies are underway. The identification and significance of novel brain and pituitary growth factors will be explored. Studies on Beta-endorphin will be continued. Finally studies on the role of human prolactin in health and diseases will be continued.